The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 12, 1992
Filed:
May. 15, 1991
Dale Kempf, Modesto, CA (US);
Hogan Mfg., Inc., Escalon, CA (US);
Abstract
A drive assembly (250) for use with a platform lift. The assembly includes a set of linkage arms (30, 32) connected between the platform (22) and a stable carriage arm (34). A pair of sprockets (50, 60) connected to the carriage arm at the linkage arm pivot points control the rotation of the linkage arm and the movement of the platform relative to the carriage arm. The sprokets are connected together by a leaf chain assembly (70) so as to show rotation of the sprockets in a simultaneous movement of the linkage arms. A compression spring (260) is attached at one end to the leaf chain assembly and at the other end to the carriage arm. When the platform is moved into the top-most position, the spring is compressed. The platform is lowered by allowing the spring to expand so that it actuates the leaf chain assembly so as to cause the linkage arms to move past their top-center positions; once the linkage arms move past their top-center positions, gravity can then force the platform downwards.